9Q9N

HSV-1 prefusion glycoprotein B bound by Nb1_gbHSV

Summary for 9Q9N

• Entry DOI: 10.2210/pdb9q9n/pdb
• Related: 9IH8 9Q9L
• EMDB information: 52863 52963 52965
• Descriptor: Glycoprotein B, Nb1_gbHSV, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: glycoprotein b, viral membrane fusion protein, herpes simplex virus 1, nanobody, viral protein
• Biological source: Human alphaherpesvirus 1 strain 17; More
• Total number of polymer chains: 6
• Total formula weight: 358942.22

Authors

Vollmer, B.,Mulvaney, T.,Ebel, H.,Nentwig, J.,Gruenewald, K. (deposition date: 2025-02-26, release date: 2025-09-03, Last modification date: 2025-10-22)

Primary citation

Vollmer, B.,Ebel, H.,Rees, R.,Nentwig, J.,Mulvaney, T.,Schunemann, J.,Krull, J.,Topf, M.,Gorlich, D.,Grunewald, K.
A nanobody specific to prefusion glycoprotein B neutralizes HSV-1 and HSV-2.
Nature, 646:433-441, 2025

PubMed Abstract: The nine human herpesviruses, including herpes simplex virus 1 and 2, human cytomegalovirus and Epstein-Barr virus, present a significant burden to global public health. Their envelopes contain at least ten different glycoproteins, which are necessary for host cell tropism, attachment and entry. The best conserved among them, glycoprotein B (gB), is essential as it performs membrane fusion by undergoing extensive rearrangements from a prefusion to postfusion conformation. At present, there are no antiviral drugs targeting gB or neutralizing antibodies directed against its prefusion form, because of the difficulty in structurally determining and using this metastable conformation. Here we show the isolation of prefusion-specific nanobodies, one of which exhibits strong neutralizing and cross-species activity. By mutational stabilization we solved the herpes simplex virus 1 gB full-length prefusion structure, which allowed the bound epitope to be determined. Our analyses show the membrane-embedded regions of gB and previously unresolved structural features, including a new fusion loop arrangement, providing insights into the initial conformational changes required for membrane fusion. Binding an epitope spanning three domains, proximal only in the prefusion state, the nanobody keeps wild-type HSV-2 gB in this conformation and enabled its native prefusion structure to be determined. This also indicates the mode of neutralization and an attractive avenue for antiviral interventions.

PubMed: 40903574
DOI: 10.1038/s41586-025-09438-5

Experimental method

ELECTRON MICROSCOPY (3 Å)